LEIDESDORFER , Viennese family prominent in the 18th and 19th centuries. The family had two branches; the older line, from *Eisenstadt, was founded by isaac leidesdorfer (d. 1748), army purveyor and agent of Samuel *Oppenheimer. He was permitted to reside in Vienna in 1719 and was often employed as a translator by the authorities. His sons, samuel (1700–1780) and loeb (1705–1789), both army purveyors, received a joint letter of protection from Maria Theresa in 1758. Loeb married the daughter of R. Margulias-Joffe and had 15 children, one of whom married a daughter of Israel von *Hoenigsberg. Samuel had seven children; his daughter Judith married Akiva *Eger the Elder and afterward Meir *Fischels, the Prague communal leader. Samuel's sons moses and joachim (Ḥayyim) were among the founders of the Vienna ḥevra kaddisha in 1763. Joachim married a granddaughter of Samson *Wertheimer; his descendants married into the Hoenigsberg and Wertheimstein families.
The younger branch of the family, which was also named Nass after Nassau, its place of origin, was established by menahem mendel leidesdorf of Pressburg (Bratislava; d. 1770), a partisan of Jacob *Emden in the Emden-Eybeschuetz conflict. His son aaron, one of the wealthiest members of the Vienna Jewish community, was head of its hospital for 40 years. In 1797 he was nominated, along with Salomon von Herz and David Wertheimer, as one of the three legal representatives of Viennese Jewry. His daughter babetta (bela) married Israel (Ignaz) Liebmann, wool merchant and industrialist. In 1817 they were given the title of Edler von Liebenberg. Their sons, one of whom married a daughter of Leopold von *Herz, were baptized. Aaron's brother markus (1754–1838) amassed great wealth as an army purveyor during the French revolutionary and Napoleonic wars; he specialized in the rapid organization of military hospitals. His requests for ennoblement were first rejected, mainly because of objections by Francis i and because of irregularities in his business transactions, but eventually, in 1817, he was granted the title of Edler von Neuwall. Markus was a representative of the Vienna Jewish community (1816–38). In 1824 his sons, august and ignaz, both baptized and married to daughters of the Herz family, were ennobled. August's son, albert von neuwall (1807–1881), an Austrian politician, was the first to speak in the Kremsier parliament (1848) in favor of Jewish emancipation.
H. Schnee, Die Hoffinanz und der moderne Staat, 4 (1963), 332–4; A. Pribram, Urkunden und Akten (1918), index; B. Wachstein, Die ersten Statuten des Bethauses in der inneren Stadt… (1926); M. Grunwald, Samuel Oppenheimer und sein Kreis (1913), 215–6; idem, Vienna (1936), index.